This study compared self-reported and measured blood pressure among American Indians of the northern plains. In 1986, a group of American Indians from the northern plains was administered the Centers for Disease Control Behavioral Risk Factor Survey (which included a question about previous blood pressure measurements) and a health risk appraisal (which included blood pressure measurement). Approximately 18% of the respondents reported being told by a doctor, nurse, or other health professional that they had high blood pressure, and 11% actually had measured blood pressures of at least 140/90 mm Hg. Overall, only 50% of hypertensive participants correctly identified themselves as hypertensive (sensitivity); specificity was 92%, predictive value positive was 43%, predictive value negative was 94%, and efficiency (the proportion of individuals who correctly classified their blood pressure status as high or normal) was 87%. These findings agree with similar studies of hypertension awareness, and they indicate that lack of this awareness remains a significant problem in the fight against cardiovascular diseases and premature death among American Indians.